1. Technical Field
The present invention relates to a detection device, a sensor cell, an electronic device, etc.
2. Related Art
Circuits that make use of pyroelectric elements for detecting infrared rays have been known in the past. For example, infrared rays with a wavelength of about 10 μm are radiated from the human body, and temperature information or the presence of a body can be acquired in non-contact fashion by detecting this radiation. Therefore, intrusion detection or physical amount measurement can be accomplished by utilizing an infrared detection circuit such as this. Also, if an infrared camera equipped with an FPA (focal plane array) is used, this makes possible night-vision devices that detect and display the forms of people and so forth at night when driving a vehicle, thermographic devices used for influenza quarantines and the like, and so on.
The technology disclosed in Japanese Laid-Open Patent Application S59-142427 and Japanese Laid-Open Patent Application H6-265411, for example, is known as prior art in the field of infrared detection circuits. With the prior art in Japanese Laid-Open Patent Application S59-142427, for instance, pyroelectric current from a pyroelectric element is read while using a chopper to repeatedly shine and block infrared rays on and from the pyroelectric element.
With the prior art in Japanese Laid-Open Patent Application H6-265411, for instance, a method is employed in which pulse voltage is applied to a pyroelectric element. Specifically, the amount of spontaneous polarization, etc., of a pyroelectric element brought about by a ferroelectric changes with the temperature of the pyroelectric element, attributable to the infrared rays directed at the pyroelectric element. In view of this, the amount of incident infrared rays can be measured by measuring the surface charge of the pyroelectric element, which varies according to the spontaneous polarization, etc.